A glass prism of refractive index `1.5` is immersed in water (refractive index 4/3). A light beam incident normally on the face `AB` is totally reflected to reach the face `BC`, Fig. if :
.

Options

A. `sin C = 8//9`
B. `sin C = 9//8`
C. `sin C = 2//3`
D. `sin C = 3//2`

Answer

A

Explanation

`(mu_2)/(mu_1) = (1)/(sin C), (1.5)/(4//3) = (1)/(sin C)` or `sin C = (8)/(9)`.